using my mind power to ensure that i have nothing is not a good way because the mind is some useful tool for other things and you ruin that
for example you should find yourself knowing that i'm me logging in or i give an idea to improve your service and if you want to ensure that i'm some body else there are better ways

i'm poor and have nothing i'm depended on the services of big powers and if they think that i want to steal their brand the only way is to provide a contract which show i have sell the brand to them and this is to ensure there is no doubt about the ownsership so that you can continue to do your job